What sizes of reamers can I install on the various reaming machines?

• The overall dimensions of the broaching machine and broach vary depending on the type of broaching machine and can be:

  

What sizes of reamers can I install on the various reaming machines?

• Below are two diagrams illustrating the relationship between broach sizes (horizontal axis) and broaching machine models (vertical axis), both for HEXAGONAL / SQUARE broaches (Fig. 1) and TORX / TORX-PLUS broaches (Fig. 2).

How long does a broach last? What factors influence the wear and tear of broaches?

• The service life of Brighetti tools depends on the conditions of use (whether proper or not), the characteristics of the material to be machined, and the amount of material removed based on the cut to be made.

  Tips for Ensuring a Longer Broach Life
  1) Use a machine tool that is sufficiently rigid to withstand strong axial forces that can cause vibrations and/or deflection.
  2) Longer tool life can be achieved by regularly checking the tool’s cutting edge and, if necessary, performing light face regrinding before the edges become excessively worn.
  Regrinding can be performed flat (zero rake angle).
  As the tool is resharpened, the profile dimension gradually decreases, by approximately 0.01 for every tenth of a millimeter removed. Conversely, dies for external profiles have a cutting edge section that gradually increases.
  Since the cutting axis must remain concentric with the workpiece axis, the tool’s projection from the broaching machine’s support surface must remain constant at:
  – 45 mm for the G16L
  – 25 mm for G12 and G16
  – 18 mm for G8
  – 10 mm for G5
  If the resharpening exceeds 1 mm, this must be compensated for by mounting a ground washer on the tool shank to restore this dimension.

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  TYPES OF SHARPENING AVAILABLE UPON REQUEST, DEPENDING ON THE TYPE OF MATERIAL TO BE PROCESSED

  STANDARD SHARPENING “Brighetti Meccanica”
  Sharpening with a flat surface and a 2° rake angle.

CUP SHARPENING
Sharpening on request for non-ferrous materials and stainless steels with Rm less than 900N/mm2 with a 2° rake angle.

FLAT GRINDING PERPENDICULAR TO THE CUTTING EDGE
Custom grinding for cast iron and stainless steels with a tensile strength (Rm) greater than 900 N/mm² and a rake angle of 2°.

What type of coating should be used on reamers depending on the type of material being reamed?

• Depending on the type of material to be machined, coatings can be applied to broaches to improve their service life in terms of the number of parts produced, such asHDP RED (STAR 4), WONDER,INOX PLUS, and TIN.
  Below are some examples of materials to be machined, along with graphs illustrating the difference between a tool made of standard HSS and a coated HSS tool.

How should we proceed when machining square blanks?

• When machining square slots, it is important to remember that the amount of material to be removed is nearly double that of a hexagonal slot, so the thrust required is greater. These operations typically require very rigid machines with considerable power.
  If possible, especially for square holes larger than 20 mm, certain precautions should be taken:
  1) The pilot hole should always be as large as possible
  2) Whenever possible, it is recommended to request that the edges be chamfered to remove the sharp edge, which is the tool’s most fragile point (see“CUSTOM SHARPENING OPTIONS THAT PROTECT DRILLS FROM WEAR”)
  3) If a square cross-section with all four full faces is required, a UT-SQ counterbore can be used.

  Of course, the same considerations apply to the production of large hexagonal holes, typically larger than 26 mm.

TYPES OF SHARPENING METHODS THAT PROTECT REAMERS FROM WEAR
To prevent or remedy possible breakage or chipping of the edges due to the material’s hardness, reamers can be sharpened as shown in the following figures:

EDGES WITH RADIUS

square / hexagonal profile

Square reamer with ROUNDED EDGES

EDGES WITH GRINDED DIAMETER

square / hexagonal profile

Square broach with GRINDED EDGES

ROUNDED EDGES
, square/hexagonal profile

Square broach with CHAMFERED EDGES

SPECIAL PROFILE MACHINING
1 – EVOLVING TOOTHING (e.g., DIN 5480):

2 – MISSING TEETH:

What are the machining parameters to follow based on the type of steel used for the broach, the profile to be produced, and the type of material to be broached?

• Depending on the type of broach (hexagonal, square, Torx, or Torx-Plus), its size, the material from which it is made, and the metal to be machined, feed rates vary as shown in the tables below.
  When selecting the feed rate and spindle speed, the following factors will be critical: the type of material to be machined, the characteristics of the machine tool, the workpiece clamping method, and the rigidity of the machine itself.
  The first step—which must be performed with the machine completely stopped—is to place the broach in direct contact with the material to be machined; this ensures the best possible machining results, as the broaching machine and the material are synchronized; this synchronization extends the service life of both the broach and the broaching machine.
  It is recommended to create a chamfer that covers the vertices of the profile to be machined. Once the broach is in place, perform the zeroing operation, set the preload to 0.1 mm, and begin machining using the parameters listed in the table below.
  Once machining is complete, the broach should be retracted at rapid feed rate; retracting the broach with a rapid motion is strictly discouraged.

Estimation of the thrust required during broaching, based on the type of material to be broached and the type of profile to be produced.

For operating parameters, please refer to the tables containing our recommendations.

The table is provided as a reference for comparing workloads among different shapes, sizes, and materials.
The values take into account the correct machining procedure (pilot hole, chamfer, pilot hole depth, etc.).

To convert to kW, note that 1 kW = 102 kgf*m (approximately)

How can I troubleshoot if the machine freezes during operation or if other similar problems occur?

• Here are some tips for troubleshooting problems during machining: